William J. Shapiro is a retired obstetrician who now lives alongside a golf course in a gated community like so many others in Florida. But exactly 60 years ago, Shapiro lived behind gates of another sort.

In February 1945, Shapiro, then an American GI, entered the Berga concentration camp outside of Weimar, Germany. But unlike the thousands of U.S. soldiers who marched into Hitler’s death camps later that spring, Shapiro came not as a liberator—but as a captive.

If not for the remarkable reporting work of New York Times correspondent Roger Cohen, the story of Shapiro—and the 349 other GIs who themselves became Holocaust victims—would not be known today.

In the immediate aftermath of the war, the U.S. Army launched an investigation to determine the extent of the atrocities committed against American soldiers at Berga. Two of Hitler’s SS guards in charge at Berga did ultimately face an American military tribunal at Dachau in September 1946. Despite a half-hearted attempt on the part of the American prosecutors—who called not a single survivor as a witness, even though many GIs had volunteered to testify—both SS guards were convicted and sentenced to death. The sentences were later commuted, and U.S. officials hushed up the results of the investigation. According to Cohen, the U.S. wanted to avoid a backlash against West Germany, which by then had become an ally in the rapidly developing Cold War.

But in his riveting new book, “Soldiers and Slaves,” Cohen takes up the questions that were left unanswered six decades ago. How did these Americans, swept up into the conflicts of a Europe they didn’t understand, react to their situation? How did the degrading incarceration of these troops intersect with broader Nazi racial policies? They are questions well worth grappling with, and they provide valuable new insight into the field of Holocaust studies—a field already seemingly saturated with information.

Cohen discovered his subject matter while serving as the Times’ bureau chief in Berlin. There, he met a filmmaker working on a documentary about the men imprisoned at the Berga concentration camp. This chance encounter was a fitting beginning for the narration of these GIs’ story—a tale of young men caught by chance in a menacing web beyond their comprehension, beyond anyone’s comprehension, really.

One path into this intriguing tangle reveals a connection between the circumstances of these soldiers and the fate of Europe’s by-then diminished millions of Jews.

The first 80 names on the list of American prisoners to be transferred from the Stalag IX-B POW camp to the underground tunnels of the small concentration camp on the banks of the river Elster were all recognizably Jewish. These 80 American Jews had already been segregated into a separate barracks at the POW camp, despite the attempts by some of them to destroy their dog tags—which the U.S. Army had engraved with an “H” for Hebrew. Many lied about their “race” when interrogated. In one instance, a soldier buried his Army-issue Jewish prayer book in the dirt of Germany.

But while the religious backgrounds of the first 80 were betrayed by their names—names like Morton Goldstein, Harold Silberstein, and Israel Cohen—the final 270 GIs, most of whom were Christian, were chosen because they “looked Jewish,” caused trouble, or were needed to fill the work camp’s quota.

Even in these final months of the war, with Hitler already installed in his concrete bunker, Himmler’s directives continued, and the human machinery of degradation and destruction persisted in its mission to obliterate the Jews, regardless of their country of origin. In other words, American Jews were no different from their Continental cousins, in spite of what the Americans themselves felt to be an almost unbreachable divide between them and the Jews they were trying to rescue from the clutches of the Third Reich. In the end, as Kafka seemingly prophesied, they were all captives in the penal colony.

Cohen masterfully illustrates this unexpected intersection of the collective Jewish narratives on both sides of the Atlantic. Within the text, he weaves together the stories of these Americans—from the time of their capture around the Battle of the Bulge in December 1944 to their eventual release from or death at the hands of the Nazis—with that of Mordecai Hauer. Today, Hauer lives in Queens—barely 10 minutes from this reviewer’s home. But back then he was a young Talmud student from the town of Goncz in northeastern Hungary, whose journey through Auschwitz and Buchenwald ended at the same concentration camp as these astonished Americans.

At Berga, even the Jewish GIs were kept apart from the camp’s more traditional inmates, but they still experienced the starvation, arbitrary beatings and executions, excruciating work details, and overall dehumanization that characterize what would later come to be called the Holocaust.

Still, it remained hard for the Americans to believe that they had been ensnared by the very process they had been sent to combat. One prisoner, Morton Brooks, “hesitated to make any connection between his own Jewishness, [that of the European prisoners], and the shared fate that had befallen them.”

As Brooks told Cohen, “that there was a holocaust going on, that this was a work-to-death program, and that you, an American soldier, were in it with the Jews of Europe, these were things that in the midst of a crazy, mixed-up war were impossible to comprehend.”

It is hard to integrate the notion that American Jews were just as vulnerable as the Jews of Europe. The distance our forebears had traveled to escape that insecurity and persecution offered a measure of safety, but that was not enough to save the GIs of Berga. As an American Jew whose grandmother escaped Nazi persecution in Germany, I’d always assumed that it was through her that my connection to the Holocaust was strongest. Upon reading of the GIs of Berga, however, I realized that it could have been my American grandfather, himself a soldier, who ended up in one of Hitler’s death camps. He wasn’t, but, then again, before Cohen came onto the scene and coaxed long-repressed memories from the surviving GIs, William Shapiro’s grandchildren might not have known his true story either.

—Staff writer Alexandra B. Moss can be reached at abmoss@fas.harvard.edu.